Yoga Nidra is a blend of deep sleep, self-hypnosis and profound relaxation. What makes Yoga Nidra distinct is that although you appear to be doing noting there is action involved.
This paradox of appearing to do nothing yet being active evokes the question ‘how is this so?’
Like all yoga practice and life itself the answer to that question is experiential. And in this case the experience is the understanding of your true nature.
What is your true nature? Why has every sage in some way or another directed you to ‘Know Thyself’?
Again the answer to these questions is experiential as to know yourself is to be aware. This is self-evident once seen and what sees this is awareness.
In the light of understanding your true nature as awareness the Yoga Nidra paradox of being active while appearing to do nothing is also resolved because Awareness is active. In short Awareness acts and its action arises simultaneously with its seeeing as awareness; in other words seeing is doing.
Still another way that this can be stated is that your true nature is mind with the experiential understanding that mind really means ‘minding’ wherein there is the activity of being aware and the simultaneous action that arises with it.
In this light your are mind or Awareness as the openness where everything is seen and what is seen is the content as your experience of life. And like breathing and all other things in the universe ‘minding’ is fourfold as four degrees or wave levels that correspond to your four brainwave patterns.
The awesome power of this understanding is that by being what you already are, which means awareness, you can remain alert through all four degrees of your mental activity and because you are aware you can command energy to take form by using the principle of ‘energy follows awareness’ and what is called the ‘Law of Attraction’.